<template>
  <div>
    <v-data-table
      :headers="headers"
      :items="desserts"
      item-key="name"
      class="elevation-1"
      :search="search"
      :custom-filter="filterOnlyCapsText"
    >
      <template v-slot:top>
        <v-text-field
          v-model="search"
          label="Search (UPPER CASE ONLY)"
          class="mx-4"
        ></v-text-field>
      </template>
      <template v-slot:body.append>
        <tr>
          <td></td>
          <td>
            <v-text-field
              v-model="calories"
              type="number"
              label="Less than"
            ></v-text-field>
          </td>
          <td colspan="4"></td>
        </tr>
      </template>
    </v-data-table>
  </div>
</template>

<script>
  export default {
    data () {
      return {
        search: '',
        calories: '',
        desserts: [
          {
            name: 'Frozen Yogurt',
            calories: 159,
            fat: 6.0,
            carbs: 24,
            protein: 4.0,
            iron: '1%',
          },
          {
            name: 'Ice cream sandwich',
            calories: 237,
            fat: 9.0,
            carbs: 37,
            protein: 4.3,
            iron: '1%',
          },
          {
            name: 'Eclair',
            calories: 262,
            fat: 16.0,
            carbs: 23,
            protein: 6.0,
            iron: '7%',
          },
          {
            name: 'Cupcake',
            calories: 305,
            fat: 3.7,
            carbs: 67,
            protein: 4.3,
            iron: '8%',
          },
          {
            name: 'Gingerbread',
            calories: 356,
            fat: 16.0,
            carbs: 49,
            protein: 3.9,
            iron: '16%',
          },
          {
            name: 'Jelly bean',
            calories: 375,
            fat: 0.0,
            carbs: 94,
            protein: 0.0,
            iron: '0%',
          },
          {
            name: 'Lollipop',
            calories: 392,
            fat: 0.2,
            carbs: 98,
            protein: 0,
            iron: '2%',
          },
          {
            name: 'Honeycomb',
            calories: 408,
            fat: 3.2,
            carbs: 87,
            protein: 6.5,
            iron: '45%',
          },
          {
            name: 'Donut',
            calories: 452,
            fat: 25.0,
            carbs: 51,
            protein: 4.9,
            iron: '22%',
          },
          {
            name: 'KitKat',
            calories: 518,
            fat: 26.0,
            carbs: 65,
            protein: 7,
            iron: '6%',
          },
        ],
      }
    },
    computed: {
      headers () {
        return [
          {
            text: 'Dessert (100g serving)',
            align: 'start',
            sortable: false,
            value: 'name',
          },
          {
            text: 'Calories',
            value: 'calories',
            filter: value => {
              if (!this.calories) return true

              return value < parseInt(this.calories)
            },
          },
          { text: 'Fat (g)', value: 'fat' },
          { text: 'Carbs (g)', value: 'carbs' },
          { text: 'Protein (g)', value: 'protein' },
          { text: 'Iron (%)', value: 'iron' },
        ]
      },
    },
    methods: {
      filterOnlyCapsText (value, search, item) {
        return value != null &&
          search != null &&
          typeof value === 'string' &&
          value.toString().toLocaleUpperCase().indexOf(search) !== -1
      },
    },
  }
</script>
